I also don’t think you need much group riding skills, the cyclist density is low, and drafting opportunities were minimal for me (I was riding alone anyway), as either you’ll be quite slow on uphills, or very fast on downhills (I am not an experienced group rider, but likely too fast to draft safely).
The area is generally not too windy due to valleys anyway.
I did over 90% of my training (39yo) with TR, starting from unstructured occasional riding about 6 months before.